This invention relates to an automatic hand dryer of the type having a heater and fan arranged to blow hot air on a user's hands to dry them. More particularly, it relates to such dryers which sense the presence of a user to energize the dryer and additionally deenergize the power circuit after a predetermined time period regardless of whether the initiating stimulus remains present.
In the past, powered hand dryers have been somewhat bulky and noisy. This is typically due to the arrangement of the fan. Fans which have been used are of high speed in order to move suitable volumes of air. Large fans, in some instances, must extend into the wall upon which they are mounted. Dryers provided with a relatively smaller fan must rotate at a relatively high speed to generate sufficient air flow, which increases noise.
Another difficulty with previous hand dryers has been the power control. While a user-actuated switch and timer is a simple, straightforward approach, a more current approach is reflected by a dryer that can be activated without touching any part of the dryer. Various sensing devices and related control circuitry have been employed to automatically energize and deenergize dryers. Difficulties of inadvertent energizations or unnecessary extended operation when not actually being used for drying have detracted from this type of equipment.